Kilgore became irritated by questions from plaintiffs' attorney Jeff Friedman about the failure of the landfill dike that led to 1.2 billion gallons of toxin-laden sludge being dumped onto the land and rivers near TVA's Kingston Fossil Plant.

"No matter how many times you ask the question, I'm not going to let you construe [the dike's failure] to just its construction," Kilgore told Friedman at one point.

Kilgore testified for a little more than two hours Wednesday in the trial of five lawsuits that cover more than 230 plaintiffs seeking damages from the Dec. 22, 2008, spill. Other lawsuits related to the spill are set for trial in November.

Friedman asked Kilgore if he knew the contractor authorized to determine what caused the spill said he was instructed by TVA to limit his review to mechanical failures, and not to look at engineering practices or policy or design problems.

Friedman pointed to a TVA inspector general's report stating that the agency's root-cause review was designed toward litigation strategy rather than finding the root cause of the spill. He asked if Kilgore knew the contractor was also told not to judge TVA or to place blame.

"All I know is that I asked the staff to find the best company or one of the best to find out what happened," Kilgore answered.

Friedman showed documents indicating some ash pond dike inspections had problems that seemingly were not dealt with year after year, appearing again in the next inspection and the next.

On cross-examination, TVA attorney Edwin Small asked Kilgore only one question: What was his instruction about the contractor hired to find the root cause of the spill?

"It didn't have anything to do with a litigation strategy," Kilgore said.